Participants: Eleonora, Tomura

We conducted characterization of  two auxiliary lasers and faraday isolators.

For two aux. lasers, beam dimension evolution along propagation were measured. Laser power during measurements were approx. 260 mW, which corresponds to 1.2A in laser current.  Attached figures shows bean waist sizes and position. The origins of x-axes were set at aperture of laser housing. The waist positions were somewhat different from what expected.

The beam polarizaiton purity was confirmed with half/quarter waveplate. It was 96.7% and 99.9% for aux1 and aux2, respectively.

Beam transmission through FI was also measured using aux laser as a light source. Pictures of two FIs were attached.

For first FI (thorlabs), transmitted power was 213 mW out of 265 mW, which means 80.4%.

For second FI (Gsaenger), it was 79%.